/**
 *
gcc player.c -lSDL2 -lSDL2main 
has not tested yet.
 * 最简单的基于FFmpeg的视频播放器2(SDL升级版)
 * Simplest FFmpeg Player 2(SDL Update)
 *
 * 雷霄骅 Lei Xiaohua
 * leixiaohua1020@126.com
 * 中国传媒大学/数字电视技术
 * Communication University of China / Digital TV Technology
 * http://blog.csdn.net/leixiaohua1020
 *
 * 第2版使用SDL2.0取代了第一版中的SDL1.2
 * Version 2 use SDL 2.0 instead of SDL 1.2 in version 1.
 *
 * 本程序实现了视频文件的解码和显示（支持HEVC，H.264，MPEG2等）。
 * 是最简单的FFmpeg视频解码方面的教程。
 * 通过学习本例子可以了解FFmpeg的解码流程。
 * 本版本中使用SDL消息机制刷新视频画面。
 * This software is a simplest video player based on FFmpeg.
 * Suitable for beginner of FFmpeg.
 * 
 * Version: 2
 */


//#include "stdafx.h"

extern "C"
{
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
#include "libswscale/swscale.h"
	//SDL
#include "sdl/SDL.h"
#include "sdl/SDL_thread.h"

};


//Refresh Event
#define SFM_REFRESH_EVENT  (SDL_USEREVENT + 1)

int thread_exit=0;

int sfp_refresh_thread(void *opaque)
{
	while (thread_exit==0) {
		SDL_Event event;
		event.type = SFM_REFRESH_EVENT;
		SDL_PushEvent(&event);
		SDL_Delay(40);
	}
	return 0;
}


int _tmain(int argc, _TCHAR* argv[])
{

	AVFormatContext	*pFormatCtx;
	int				i, videoindex;
	AVCodecContext	*pCodecCtx;
	AVCodec			*pCodec;
	char filepath[]="src01_480x272_22.h265";

	av_register_all();
	avformat_network_init();
	pFormatCtx = avformat_alloc_context();

	if(avformat_open_input(&pFormatCtx,filepath,NULL,NULL)!=0){
		printf("Couldn't open input stream.（无法打开输入流）\n");
		return -1;
	}
	if(av_find_stream_info(pFormatCtx)<0)
	{
		printf("Couldn't find stream information.（无法获取流信息）\n");
		return -1;
	}
	videoindex=-1;
	for(i=0; i<pFormatCtx->nb_streams; i++) 
		if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO)
		{
			videoindex=i;
			break;
		}
	if(videoindex==-1)
	{
		printf("Didn't find a video stream.（没有找到视频流）\n");
		return -1;
	}
	pCodecCtx=pFormatCtx->streams[videoindex]->codec;
	pCodec=avcodec_find_decoder(pCodecCtx->codec_id);
	if(pCodec==NULL)
	{
		printf("Codec not found.（没有找到解码器）\n");
		return -1;
	}
	if(avcodec_open2(pCodecCtx, pCodec,NULL)<0)
	{
		printf("Could not open codec.（无法打开解码器）\n");
		return -1;
	}
	AVFrame	*pFrame,*pFrameYUV;
	pFrame=avcodec_alloc_frame();
	pFrameYUV=avcodec_alloc_frame();
	uint8_t *out_buffer=(uint8_t *)av_malloc(avpicture_get_size(PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height));
	avpicture_fill((AVPicture *)pFrameYUV, out_buffer, PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height);
//------------SDL----------------
	if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) {  
		printf( "Could not initialize SDL - %s\n", SDL_GetError()); 
		return -1;
	} 

	int screen_w=0,screen_h=0;
	SDL_Window *screen; 
	//SDL 2.0 Support for multiple windows
	screen_w = pCodecCtx->width;
	screen_h = pCodecCtx->height;
	screen = SDL_CreateWindow("Simplest ffmpeg player's Window", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
		screen_w, screen_h,
		SDL_WINDOW_OPENGL);

	if(!screen) {  
		printf("SDL: could not create window - exiting:%s\n",SDL_GetError());  
		return -1;
	}


	SDL_Renderer* sdlRenderer = SDL_CreateRenderer(screen, -1, 0);  
	//IYUV: Y + U + V  (3 planes)
	//YV12: Y + V + U  (3 planes)
	SDL_Texture* sdlTexture = SDL_CreateTexture(sdlRenderer, SDL_PIXELFORMAT_IYUV, SDL_TEXTUREACCESS_STREAMING,pCodecCtx->width,pCodecCtx->height);  

	SDL_Rect sdlRect;  
	sdlRect.x = 0;  
	sdlRect.y = 0;  
	sdlRect.w = screen_w;  
	sdlRect.h = screen_h;  

	int ret, got_picture;

	AVPacket *packet=(AVPacket *)av_malloc(sizeof(AVPacket));
	//Output Info-----------------------------
	printf("File Information（文件信息）---------------------\n");
	av_dump_format(pFormatCtx,0,filepath,0);
	printf("-------------------------------------------------\n");
	
	struct SwsContext *img_convert_ctx;
	img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height, PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL); 
	//--------------
	SDL_Thread *video_tid = SDL_CreateThread(sfp_refresh_thread,NULL,NULL);
	//
	//Event Loop
	SDL_Event event;
	for (;;) {
		//Wait
		SDL_WaitEvent(&event);
		if(event.type==SFM_REFRESH_EVENT){
			//------------------------------
			if(av_read_frame(pFormatCtx, packet)>=0){
				if(packet->stream_index==videoindex){
					ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture, packet);
					if(ret < 0){
						printf("Decode Error.（解码错误）\n");
						return -1;
					}
					if(got_picture){
						sws_scale(img_convert_ctx, (const uint8_t* const*)pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameYUV->data, pFrameYUV->linesize);
						//SDL---------------------------
						SDL_UpdateTexture( sdlTexture, &sdlRect, pFrameYUV->data[0], pFrameYUV->linesize[0] );  
						SDL_RenderClear( sdlRenderer );  
						SDL_RenderCopy( sdlRenderer, sdlTexture, &sdlRect, &sdlRect );  
						SDL_RenderPresent( sdlRenderer );  
						//SDL End-----------------------
					}
				}
				av_free_packet(packet);
			}else{
				//Exit Thread
				thread_exit=1;
				break;
			}
		}

	}

	sws_freeContext(img_convert_ctx);

	SDL_Quit();
	//--------------
	av_free(out_buffer);
	av_free(pFrameYUV);
	avcodec_close(pCodecCtx);
	avformat_close_input(&pFormatCtx);

	return 0;
}

